Mainstream Impoundment Research Articles

Variation in Largemouth Bass Recruitment in Four Mainstream Impoundments of the Tennessee River

Abstract Variation in recruitment of largemouth bass Micropterus salmoides was quantified in four mainstream impoundments along an 800-km segment of the Tennessee River and compared with various types of hydrologic and aquatic plant abundance data in an attempt to explain factors related to the formation of strong and weak year-classes. Residuals from four catch-curve regressions for age-2–11 fish collected in 1993 or 1994 were used to describe year-class strength. The formation of strong and weak year-classes was generally synchronous in these four reservoirs. Year-class strength was inversely related to average June–July discharge and positively associated with retention (reservoir volume/discharge) for data pooled from all reservoirs. Thus, weak year-classes were produced during wet early-summer conditions after largemouth bass hatched, whereas stronger year-classes were produced during dryer early-summer conditions. Late-summer aquatic plant abundance and water level fluctuations during April–May whil...

URBAN INFLUENCE ON PHOSPHORUS AND SEDIMENT LOADING OF WEST POINT LAKE, GEORGIA1

ABSTRACT: West Point Lake is a 10,360 ha mainstream impoundment of the Chattahoochee River located 95 kilometers downstream of Atlanta, Georgia. Origins and magnitude of external total phosphorus (TP) and total suspended solids (TSS) loads from the West Point Lake basin were estimated over a one‐year period. Partitioning the drainage basin allowed the sources of these loads to be determined. The upper subbasin area, from Franklin, Georgia, to the headwaters of the Chattahoochee River, contributed 96 percent of the discharge and 97 percent of the TP and TSS loads into West Point Lake. The lower subbasin area, from Franklin to West Point Lake dam, only contributed 3 percent of the TP and TSS loads. Ninety‐one percent and 87 percent of the TP and TSS loads, respectively, from the upper subbasin originated from the Atlanta area. Point sources discharged 70 percent and 3 percent of the upper subbasin TP and TSS loads, respectively. A large portion (66 percent) of the TP from the upper subbasin was in the bioavailable form.

Evaluation of the Mussel Fishery in Wheeler Reservoir, Tennessee River

Abstract We evaluated the freshwater mussel fishery on Wheeler Reservoir, a 27,155-hectare mainstream impoundment of the Tennessee River in Alabama. During July 1991 through June 1992, we used a roving creel survey to conduct 285 interviews over 57 weekdays and 12 weekend days. Total harvest during the 12-month survey period was estimated to be 570 metric tons, and included 15 mussel species. The most frequently harvested species were the washboard Megalonaias nervosa, Ohio pigtoe Pleurobema cordatum, and butterfly Elliesaria lineolata. Harvest peaked in June at 290,414 mussels. Among collection techniques, total estimated effort was highest for divers (71,160 musseler-hours). The total estimated value of the 12-month mussel harvest (in terms of money paid to harvesters) from Wheeler Reservoir was US$2,119,921.

Impact of Mainstream Impoundment on the Distribution and Movements of the Resident Flannelmouth Sucker (Catostomidae: Catostomus latipinnis) Population in the White River, Colorado

Impact of Mainstream Impoundment on the Distribution and Movements of the Resident Flannelmouth Sucker (Catostomidae: Catostomus latipinnis) Population in the White River, Colorado

Regulated rivers in the United Kingdom

AbstractThis paper identifies the principal regulated rivers in Britain and summarizes their physical and ecological characteristics. Virtually all major rivers in the United Kingdom are shown to be regulated directly or indirectly by mainstream impoundments, interbasin transfers, pumped storage reservoirs, or groundwater abstractions. Flow records for sixty per cent of all gauging stations are significantly affected by flow manipulations. Three phases in the development of river regulation are identified: firstly, the development of direct supply and compensation reservoirs from 1840; secondly, the development of large dams and large‐scale interbasin water transfers from 1890; and thirdly, the modern era of multipurpose river regulation that began in 1965.Any assessment of the environmental effects of river regulation must consider the spatial variation of natural river systems throughout the U.K., climatic changes, and the cumulative effect of river regulation and other impacts over an historic timescale. Today, the rivers of the U.K. are shown to have an underlying character that reflects the marked climatic, geologic, and topographic differences between the upland north and west, and lowland south and east; differences in part that relate to their different histories during the Pleistocene. However, many rivers show the effects of human impacts that began about 5000 years ago. Most rivers have experienced changes since about 1930 consequent upon afforestaton, land drainage, and channelization. These, together with short‐term climatic changes, make defining ecological impacts of river regulation problematic. Pollution has had the most dramatic effects. Nevertheless, it is suggested that new concepts of environmentally sound river regulation could lead to the restoration and even enhancement of rivers in the United Kingdom.

Effects of Small Impoundments on Hydropsychid Caddisfly Production In Valley Creek, Minnesota

Annual production by filter—feeding caddisfly larvae (Trichoptera: Hydropsychidae) was estimated by the size—frequency method and compared in riffles immediately above and below small (<1 ha) impoundments or ponds at three sites in Valley Creek, Minnesota in 1982—1983. At all three sites, production was significantly higher below impoundments than above. At the most upstream site, annual production by Hydropsyche slossonae was 0.9 g/m2 (dry mass) in the upper riffle but was 40.0 g/m2 in the riffle located below inputs by ponds beside the main stream. At the middle site, production by H. slossonae and a small population of Cheumatopsyche pettiti was 16.2 g/m2 in the upper riffle, but was 31.7 g/m2 below two mainstream impoundments and a side pond. At the lowermost site, production by co—dominants H. slossonae and C. pettiti together with Hydropsyche riola totalled 5.8 g/m2 in the upper riffle but 34.9 g/m2 below a mainstream impoundment. Although the number of hydropsychid species increased at successive downstream sites, the proportionate representation of species in the upper riffle at a given site was almost identical to that in the lower riffle. The higher production in lower riffles was attributed to factors in pond or impoundment outflows that provided favorable conditions for species already established in the reach of creek containing the impoundment. The most likely factor was postulated to be an increase in abundance or quality of seston. Other factors were better growths of moss and filamentous algae, which provided attachment sites for retreat construction, and the absence of abrasive sand after deposition in impoundments.

Colonization and succession of benthic macroinvertebrates in a new reservoir

The purpose of this study was to examine the colonization and succession of benthic macroinvertebrates in shallow areas (<7 m) of Lake Anna, a new mainstream impoundment in the southeastern U.S.A. Benthic macroinvertebrates were sampled for the first three years after filling by means of artificial substrates placed on the bottom and retrieved with SCUBA. Lake Anna was well colonized by benthic macroinvertebrates during the summer season immediately after impoundment. The total density of organisms increased in each of the first three years. Major changes in the fauna occurred between the first and second years, but the changes between the second and third years were more subtle. The fauna could be divided into two distinct groups based upon the time when the organisms were most consistently abundant. The first colonizers appeared to be dependent upon the components of the former terrestrial ecosystem for food and habitat. As autochthonous factors began to regulate succession, diversity increased and the dominant species shifted to an assemblage of second colonizers. These factors included: (1) decomposition of terrestrial vegetation and detritus leaving bare substrate, (2) sedimentation, (3) improved food quality of the organic matter in the sediment because of ingestion and egestion by the organisms themselves, (4) increased plankton populations, and (5) appearance of macrophytes. As the second colonizers became firmly established in the third year, distinct patterns of spatial distribution began to appear among species with similar niches.

Two Patagonian basins - Negro (Argentina) and Valdivia (Chile) - as habitats for Plecoptera

Even though the insects of the Neotropical area had been neglected, several authors have studied different aspects of the Southern Neotropical Plecoptera (Aubert, Benedetto, Enderlein, Froehlich, Gerstaecker, Illies, Navás, Klapálek, Werner, Zwick), specially the Andean oligostenothermal cool-adapted stoneflies. Most of the Argentinian river basins are widely spread out. The upper reaches of the Negro hydrographic system are on the east slope of the Andes and discharge into the Limay and Neuquén rivers downstream. The Negro river is formed by the convergence of both rivers and presents a sequence of reservoirs (main-stream impoundments on Limay and off-channel ones at Neuquén) ; it reaches the South Atlantic coast at approximately 41 ° S. The headstreams of the Valdivia system are on the west slope of the Andes. This river, much shorter than the Negro, joins the Pacific at 40° S. Transition from rhithron to potamon is rapid, if indeed the potamon exists. Macrozoobenthic samples of these two North Patagonian river basins, Negro (Argentina) and Valdivia (Chile) were taken in the period 1977-1983 in order to compare habitats of aquatic insects and other invertebrates on both slopes of the Andes and at the same latitude. Ten genera of Plecoptera were recorded by the author as nymphs : Gripopterygidae (Antarctoperla, Limnoperla, Potamoperla, Pelurgoperla, and Araucanioperla ?), Diamphipnoidae (Diamphipnoa and Diamphipnopsis), Austroperlidae (Klapopteryx), Notonemouridae (Austronemoura) and Perlidae (Kempnyella). Most of these genera of Plecoptera were collected in the upper rhithral. Only Antarctoperla and Limnoperla were found in reservoirs, in one lake and in medium-size to wide rivers. Gripoperygids were more frequent on the Argentine side ; the other families were more abondant on the opposite slope ; this situation can probably be explained by the different ecological conditions brought about by cattle raising and dam construction.

An Ecological Analysis of Lotic Environments: I. Design and Testing

ABSTRACT A biotic analysis of lotic environments was designed, using ecological tolerances and requirements of the numerically dominant macrobenthic invertebrates. This method, “Ecological Community Analysis” (ECA), uses the habitat, habits, mode of feeding, temperature preference and silt- and hypoxia-tolerances of the dominant organisms to isolate the most important environmental factors associated with biotic communities. ECA showed that above a mainstream impoundment on the Speed River (Southern Ontario) the benthos was dominated by lotic-selecting, warm-water and hypoxia-intolerant organisms. Presence of these organisms indicates that the biologically relevant environmental factors at the upstream station were: swift current, warm water and high dissolved oxygen levels. Two stations, 100 m and 400 m below the dam, were characterized by higher proportions, relative to other stations, of cool water, shredding, and algae-tolerant organisms. Significantly higher proportions of climbing and lentic-selecti...

Nitrogen and Phosphorus in a Stretch of the Guadalupe River, Texas, with Five Main-Stream Impoundments by

Nitrogen and phosphorus were studied in a 168-km stretch of the Guadalupe River that had five main-stream impoundments. Flow through the study area was controlled by releases from these five reservoirs and from Canyon Reservoir, a deep-storage reservoir, located 30 km upstream. Parameters measured monthly on a diel basis at 16 stations were nitrate nitrogen, nitrite nitrogen, ammonia nitrogen, Kjeldahl nitrogen, inorganic phosphate phosphorus, organic phosphate phosphorus, and total phosphate phosphorus. Inorganic nitrogen concentrations observed in this study were as high or higher than that previously reported for other bodies of water. Nitrate nitrogen entered the study area in relatively high concentrations from Comal Springs which was a major source of water for the Guadalupe River. Water from Canyon Reservoir, the other major source of water, was relatively low in nitrate nitrogen. The concentration of nitrate nitrogen was, therefore, dependent in part upon the portion of the total river flow originating from the two sources. Increased discharge from Canyon Reservoir and utilization by plants in areas of high chlorophyll a resulted in low nitrate-nitrogen levels. Retention of water in reservoirs reduced the concentration of nitrate nitrogen due to increased utilization by plants in areas of low flow. Nitrate nitrogen, in general, reached seasonal minima in summer and maxima in winter. Nitrite nitrogen showed considerable variation with no meaningful pattern except that higher concentrations occurred in association with high chlorophyll a and high Kjeldahl nitrogen, regions and periods of low river flow, and large phytoplankton populations. There was no increase in concentration of any form of nitrogen in the vicinity of sewage outfalls and no downstream accrual. Phosphorus levels in the study area were as high or higher than those reported in studies of other bodies of water. Sewage treatment plants at New Braunfels and Seguin, Texas, were major sources of phosphorus to the Guadelupe River. Total phosphate phosphorus was determined to be the most critical phosphate parameter in assessing eutrophication. Seasonally, it ranged from a winter high to a summer low. Concentrations were highest immediately below sewage outfalls and decreased as water progressed downstream. Inorganic-phosphate-phosphorus concentrations showed no clear seasonal trend but were clearly associated with sewage outfalls. Since large standing crops of phytoplankton were observed in areas of low inorganic phosphate phosphorus, it was not considered to limit photosynthesis. Total organic phosphate phosphorus varied seasonally, with high concentrations occurring during the spring and low concentrations in the fall. Total organic phosphate phosphorus showed no correlation with sewage outfalls, but was correlated to a degree with total Kjeldahl nitrogen and chlorophyll a. No consistent pattern of diel fluctuations was evident for any phosphorus or nitrogen compounds analyzed.

The physicochemical limnology of a stretch of the Guadalupe River, Texas, with five main-stream impoundments

A study of limnological conditions was conducted on a 168-km stretch of the Guadalupe River in central Texas for one year beginning in February, 1969. This river stretch was unique in that it had a sequence of five shallow, nonstratified, main-stream reservoirs. Flow through the study area was controlled by releases from these five reservoirs and from Canyon Reservoir, a deep-storage reservoir, located 30 km upstream. Physicochemical properties measured monthly on a diel basis at 16 stations were: dissolved oxygen, chlorophyll a, pH alkalinity, specific conductance, water temperature, turbidity, transparency, water velocity, and discharge.

Differences in Fish Populations Upstream and Downstream of a Mainstream Impoundment

Four species of cyprinid fishes, Hybopsis biguttata, H. micropogon, Pimephales notatus, and Notropis spilopterus found in a river upstream of a flood control dam are absent downstream. With the release downstream of cold hypolimnial waters from the dam there was a lag of about 4 weeks in the spring rise of water temperatures and a maximum summer temperature 7 degrees C lower than upstream. Of the fish present in the river these four species had the most southerly distributions, all south of the 64 F (17.8 C) July isotherm, and it is concluded that the lower water temperatures are mainly responsible for their absence downstream of the dam.

A Comparison of the Hoop-Net Catches in Several Fish Habitats of Wheeler Reservoir

Abstract Hoop nets were fished in all four major habitats in Wheeler Reservoir, a T.V.A. main-stream impoundment, during a six-months' period in 1941. Long-nose gar, mooneye, skipjack, mud catfish, black bullhead, white bass, sauger, and crappie were best represented in the catch from the fast tailwater; drum were taken in greatest numbers in the upper “third,” which had retained many of the characteristics of the original river; rough-fish species were most commonly caught in the middle section with its extensive shallow backwaters; and Kentucky bass were best represented in the lower “third” where the water is less turbid than in other portions of the reservoir.